The real life 'Aristocats' of St. Petersburg's Hermitage Museum

Walk in the footsteps of Russian tsars at one of the world's largest museums, where cats prowl the premises by royal decree, doing a job of their own dating back hundreds of years.

(CNN) — While you're strolling the grand halls of the State Hermitage Museum, in St. Petersburg, Russia, you might hear the faint sound of a meow coming from pipes below.

Roaming the sprawling basement of what was once the Winter Palace -- the official residence of Russia's ruling tsars -- are nearly 50 cats who are treated like royalty. Down in the main room (the "koshachiy dom," or "cat's house") they are fed and cared for by the staff at the Hermitage, with veterinarians on call.

The palace also has a special room for the more anti-social cats that prefer little contact with their fellow felines. Then there are the ones who meander the halls of the basement, lying on large pipes and trotting freely about the nooks and crannies of the palace.